/*
   * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
   *
   * Portions from U-Boot cmd_fdt.c (C) Copyright 2007
   * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
   * Based on code written by:
   *   Pantelis Antoniou <pantelis.antoniou@gmail.com> and
   *   Matthew McClintock <msm@freescale.com>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License as
   * published by the Free Software Foundation; either version 2 of
   * the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
   * MA 02111-1307 USA
   */
  
  #include <assert.h>
  #include <ctype.h>
  #include <getopt.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include <libfdt.h>
  
  #include "util.h"
  
  enum display_mode {
  	MODE_SHOW_VALUE,	/* show values for node properties */
  	MODE_LIST_PROPS,	/* list the properties for a node */
  	MODE_LIST_SUBNODES,	/* list the subnodes of a node */
  };
  
  /* Holds information which controls our output and options */
  struct display_info {
  	int type;		/* data type (s/i/u/x or 0 for default) */
  	int size;		/* data size (1/2/4) */
  	enum display_mode mode;	/* display mode that we are using */
  	const char *default_val; /* default value if node/property not found */
  };
  
  static void report_error(const char *where, int err)
  {
  	fprintf(stderr, "Error at '%s': %s
  ", where, fdt_strerror(err));
  }
  
  /**
   * Displays data of a given length according to selected options
   *
   * If a specific data type is provided in disp, then this is used. Otherwise
   * we try to guess the data type / size from the contents.
   *
   * @param disp		Display information / options
   * @param data		Data to display
   * @param len		Maximum length of buffer
   * @return 0 if ok, -1 if data does not match format
   */
  static int show_data(struct display_info *disp, const char *data, int len)
  {
  	int i, size;
  	const uint8_t *p = (const uint8_t *)data;
  	const char *s;
  	int value;
  	int is_string;
  	char fmt[3];
  
  	/* no data, don't print */
  	if (len == 0)
  		return 0;
  
  	is_string = (disp->type) == 's' ||
  		(!disp->type && util_is_printable_string(data, len));
  	if (is_string) {
  		if (data[len - 1] != '\0') {
  			fprintf(stderr, "Unterminated string
  ");
  			return -1;
  		}
  		for (s = data; s - data < len; s += strlen(s) + 1) {
  			if (s != data)
  				printf(" ");
  			printf("%s", (const char *)s);
  		}
  		return 0;
  	}
  	size = disp->size;
  	if (size == -1) {
  		size = (len % 4) == 0 ? 4 : 1;
  	} else if (len % size) {
  		fprintf(stderr, "Property length must be a multiple of "
  				"selected data size
  ");
  		return -1;
  	}
  	fmt[0] = '%';
  	fmt[1] = disp->type ? disp->type : 'd';
  	fmt[2] = '\0';
  	for (i = 0; i < len; i += size, p += size) {
  		if (i)
  			printf(" ");
  		value = size == 4 ? fdt32_to_cpu(*(const uint32_t *)p) :
  			size == 2 ? (*p << 8) | p[1] : *p;
  		printf(fmt, value);
  	}
  	return 0;
  }
  
  /**
   * List all properties in a node, one per line.
   *
   * @param blob		FDT blob
   * @param node		Node to display
   * @return 0 if ok, or FDT_ERR... if not.
   */
  static int list_properties(const void *blob, int node)
  {
  	const struct fdt_property *data;
  	const char *name;
  	int prop;
  
  	prop = fdt_first_property_offset(blob, node);
  	do {
  		/* Stop silently when there are no more properties */
  		if (prop < 0)
  			return prop == -FDT_ERR_NOTFOUND ? 0 : prop;
  		data = fdt_get_property_by_offset(blob, prop, NULL);
  		name = fdt_string(blob, fdt32_to_cpu(data->nameoff));
  		if (name)
  			puts(name);
  		prop = fdt_next_property_offset(blob, prop);
  	} while (1);
  }
  
  #define MAX_LEVEL	32		/* how deeply nested we will go */
  
  /**
   * List all subnodes in a node, one per line
   *
   * @param blob		FDT blob
   * @param node		Node to display
   * @return 0 if ok, or FDT_ERR... if not.
   */
  static int list_subnodes(const void *blob, int node)
  {
  	int nextoffset;		/* next node offset from libfdt */
  	uint32_t tag;		/* current tag */
  	int level = 0;		/* keep track of nesting level */
  	const char *pathp;
  	int depth = 1;		/* the assumed depth of this node */
  
  	while (level >= 0) {
  		tag = fdt_next_tag(blob, node, &nextoffset);
  		switch (tag) {
  		case FDT_BEGIN_NODE:
  			pathp = fdt_get_name(blob, node, NULL);
  			if (level <= depth) {
  				if (pathp == NULL)
  					pathp = "/* NULL pointer error */";
  				if (*pathp == '\0')
  					pathp = "/";	/* root is nameless */
  				if (level == 1)
  					puts(pathp);
  			}
  			level++;
  			if (level >= MAX_LEVEL) {
  				printf("Nested too deep, aborting.
  ");
  				return 1;
  			}
  			break;
  		case FDT_END_NODE:
  			level--;
  			if (level == 0)
  				level = -1;		/* exit the loop */
  			break;
  		case FDT_END:
  			return 1;
  		case FDT_PROP:
  			break;
  		default:
  			if (level <= depth)
  				printf("Unknown tag 0x%08X
  ", tag);
  			return 1;
  		}
  		node = nextoffset;
  	}
  	return 0;
  }
  
  /**
   * Show the data for a given node (and perhaps property) according to the
   * display option provided.
   *
   * @param blob		FDT blob
   * @param disp		Display information / options
   * @param node		Node to display
   * @param property	Name of property to display, or NULL if none
   * @return 0 if ok, -ve on error
   */
  static int show_data_for_item(const void *blob, struct display_info *disp,
  		int node, const char *property)
  {
  	const void *value = NULL;
  	int len, err = 0;
  
  	switch (disp->mode) {
  	case MODE_LIST_PROPS:
  		err = list_properties(blob, node);
  		break;
  
  	case MODE_LIST_SUBNODES:
  		err = list_subnodes(blob, node);
  		break;
  
  	default:
  		assert(property);
  		value = fdt_getprop(blob, node, property, &len);
  		if (value) {
  			if (show_data(disp, value, len))
  				err = -1;
  			else
  				printf("
  ");
  		} else if (disp->default_val) {
  			puts(disp->default_val);
  		} else {
  			report_error(property, len);
  			err = -1;
  		}
  		break;
  	}
  
  	return err;
  }
  
  /**
   * Run the main fdtget operation, given a filename and valid arguments
   *
   * @param disp		Display information / options
   * @param filename	Filename of blob file
   * @param arg		List of arguments to process
   * @param arg_count	Number of arguments
   * @param return 0 if ok, -ve on error
   */
  static int do_fdtget(struct display_info *disp, const char *filename,
  		     char **arg, int arg_count, int args_per_step)
  {
  	char *blob;
  	const char *prop;
  	int i, node;
  
  	blob = utilfdt_read(filename);
  	if (!blob)
  		return -1;
  
  	for (i = 0; i + args_per_step <= arg_count; i += args_per_step) {
  		node = fdt_path_offset(blob, arg[i]);
  		if (node < 0) {
  			if (disp->default_val) {
  				puts(disp->default_val);
  				continue;
  			} else {
  				report_error(arg[i], node);
  				return -1;
  			}
  		}
  		prop = args_per_step == 1 ? NULL : arg[i + 1];
  
  		if (show_data_for_item(blob, disp, node, prop))
  			return -1;
  	}
  	return 0;
  }
  
  static const char *usage_msg =
  	"fdtget - read values from device tree
  "
  	"
  "
  	"Each value is printed on a new line.
  
  "
  	"Usage:
  "
  	"	fdtget <options> <dt file> [<node> <property>]...
  "
  	"	fdtget -p <options> <dt file> [<node> ]...
  "
  	"Options:
  "
  	"\t-t <type>\tType of data
  "
  	"\t-p\t\tList properties for each node
  "
  	"\t-l\t\tList subnodes for each node
  "
  	"\t-d\t\tDefault value to display when the property is "
  			"missing
  "
  	"\t-h\t\tPrint this help
  
  "
  	USAGE_TYPE_MSG;
  
  static void usage(const char *msg)
  {
  	if (msg)
  		fprintf(stderr, "Error: %s
  
  ", msg);
  
  	fprintf(stderr, "%s", usage_msg);
  	exit(2);
  }
  
  int main(int argc, char *argv[])
  {
  	char *filename = NULL;
  	struct display_info disp;
  	int args_per_step = 2;
  
  	/* set defaults */
  	memset(&disp, '\0', sizeof(disp));
  	disp.size = -1;
  	disp.mode = MODE_SHOW_VALUE;
  	for (;;) {
  		int c = getopt(argc, argv, "d:hlpt:");
  		if (c == -1)
  			break;
  
  		switch (c) {
  		case 'h':
  		case '?':
  			usage(NULL);
  
  		case 't':
  			if (utilfdt_decode_type(optarg, &disp.type,
  					&disp.size))
  				usage("Invalid type string");
  			break;
  
  		case 'p':
  			disp.mode = MODE_LIST_PROPS;
  			args_per_step = 1;
  			break;
  
  		case 'l':
  			disp.mode = MODE_LIST_SUBNODES;
  			args_per_step = 1;
  			break;
  
  		case 'd':
  			disp.default_val = optarg;
  			break;
  		}
  	}
  
  	if (optind < argc)
  		filename = argv[optind++];
  	if (!filename)
  		usage("Missing filename");
  
  	argv += optind;
  	argc -= optind;
  
  	/* Allow no arguments, and silently succeed */
  	if (!argc)
  		return 0;
  
  	/* Check for node, property arguments */
  	if (args_per_step == 2 && (argc % 2))
  		usage("Must have an even number of arguments");
  
  	if (do_fdtget(&disp, filename, argv, argc, args_per_step))
  		return 1;
  	return 0;
  }